Fascinating What if Question.....

What if cars with bumper stickers were more likely to be involved in accidents involving road-rage?.  Here is the Washington Post's summary.

Watch out for cars with bumper stickers.

That's the surprising conclusion of a recent study by Colorado State University social psychologist William Szlemko. Drivers of cars with bumper stickers, window decals, personalized license plates and other "territorial markers" not only get mad when someone cuts in their lane or is slow to respond to a changed traffic light, but they are far more likely than those who do not personalize their cars to use their vehicles to express rage -- by honking, tailgating and other aggressive behavior.

Suppose this is true.  Would it be permissible to increase auto insurance premiums?I would say yes (again, assuming it is true and verifiable using traditional methods).

This would lead to people being puzzled about how their viewpoint can be associated with risk.  In fact, this is the same type of argument that is made about insurance credit scores and auto insurance premiums.  How can my bumper sticker which says Visualize Whirled Peas cause me to behave riskier?

Here is the gated version.  I could not find a working paper.  The paper actually has a nice literature review of things which affect driver aggression (own personal music choice (rather than teenage daughter's), congestion, provocation, vehicle characteristics (tinted windows), initial endowments of anger, time constraints, and heat among others.) 

What if part of the underwriting process one had to go through a personality inventory.  Less agressive people would get lower rates.  That would make them better off and I wonder how long it will take Progressive to start marketing its Peaceful Driver Program.

Also see Hit & Run (a great name for an auto accident blog) and Tyler Cowan at Marginal Revolution.